1. Aiello, J.R., De Risi, D.T., Epstein, Y.M. & Karlin, R.A. (1977). Crowding and the role of interpersonal distance preference. Sociometry, 40, 271–281.
2. Altman, I. (1975). The Environment and Social Behaviour: Privacy, Personal Space, Territory, Crowding. Monterey: Brooks/Cole.
3. Argyle, M. & Dean, J. (1965). Eye-contact, distance and affiliation. Sociometry, 28, 289–304.
4. Barker, R.G. & Barker, L.S. (1961). Behaviour units for the comparative study of culture. In A. Burton & R. Harris (eds.), Studying Personality Cross-Culturally, pp. 457–476. New York: Harper & Row.
5. Baron, R.M. (1979). Ecological approaches to understanding human crowding. Journal of Population, 2, 235–258.